The primary role of the Biostatistics and Data Management Core is to provide collaboration on quantitative aspects of the design, conduct, and analysis of the clinical and laboratory studies undertaken as part of this proposal. In both the laboratory and the clinical studies this will include sample size calculation and analysis of data for abstracts manuscripts and presentations. For the clinical studies, will also include sample size calculation and analysis of data for abstracts, manuscripts and presentations. For the clinical studies, will till also include protocol review, forms development, dat extraction, data computerization and quality control. Specific aims of the core include: 1. To provide biostatistical expertise for clinical protocol design and for planning and interpreting sequences of related protocols. 2. To provide biostatistical assistance in the design, analysis, and interpretation of laboratory studies. 3. To provide forms design, data management support, and quality control for clinical protocols. 4. To provide clinical data management for collection of individual patient information. 5. To provide interim reports for ongoing studies, and more detailed statistical analyses of finally study results; to collaborate on dissemination of these results through abstracts, manuscripts, and presentations. 6. To conduct statistical analyses using the BMT data base to compare outcomes and identify prognostic factors across protocols when appropriate.